The field of invention is the high speed, automatic extraction of oil from the peel or rind of citrus fruit. Such machines accumulate unwanted residues on rollers (or rolls) used to extract the oil. Those rollers require periodic cleaning, resulting in expensive downtime of the extractor. The present invention significantly reduces said downtime by providing a “self-cleaning” (or “clean in place”) mode of operation, and increases efficiency of operation as well as safety of operation, as described below in greater detail. The present invention also includes another mode of operation in which a wiper bar periodically conveys or pushes citrus fruit through the extractor. This mode is utilized only when citrus fruit, for various reasons, remains on the rollers and it is necessary to push or convey the fruit through the extractor.